Hi
The Satellite Pro 4360 was delivered with the 64MB internal memory and this memory in not removable.
As you already said, there is only one slot which is upgradeable.
Anyway... it seems that it’s not possible to upgrade the memory up to 512MB.
You can upgrade the memory to 320MB (64MB internal memory + 256MB external memory). This is a limit.
I found a very useful page which confirms this info:
http://www.orcalogic.co.uk/asp/prodtype.asp?prodtype=5775&ft=m&st=3
PS: I have forgotten to say that the notebook supports
144-Pin PC100 SODIMM
bye